There are many occupations and circumstances in which people routinely get their hands, and particularly fingertips, heavily soiled. For example, commercial gardening, in the form of retail nurseries and those who provide gardening services at private homes, has become a large industry in the United States and other parts of the world. As the global economy has developed, more and more homeowners are relying upon professional gardening services to both supply them with shrubs and other provisions required for home gardening and to care for home gardens and lawns. Furthermore, notwithstanding the professional services used by homeowners, many homeowners themselves participate in gardening and yard care. In either case, the professional nursery personnel and homeowners often find themselves having hands and fingernails caked with soil and other yard matter, which, particularly if ignored, becomes increasingly difficult to remove. Examples of other occupations and circumstances in which people get their hands heavily soiled include automobile mechanics, construction workers, and industrial workers (e.g., steel mill workers), among many others.
Of course, standard soap and water provides a partially suitable solution to the problem of cleaning hands of the built-up soil but, nevertheless, virtually never quite completely removes all of the soil from hands and especially from around and under fingernails. Many types of hand-operated fingernail brushes are available for assisting people in cleaning dirt from their fingertips and particularly from crevices at the lateral margins of the fingernail plates and in the hyponychium regions under the front edges of the nails. The cleaning effectiveness of existing fingernail brushes varies from brush to brush, and improvements are still needed to increase fingernail brush cleaning effectiveness and increase their adaptability to the manner in which individual users tend to use the brushes.